A foldable chair may be configured as a walking stick chair for use of people having inferior physical condition. U.S. Pat. No. 2,380,437 discloses a conventional walking stick chair including a stick and a sleeve slidable along the stick. The conventional walking stick chair is convertible between a folded state and an unfolded state by moving the sleeve along the stick. The sleeve can be positioned relative to the stick for retaining the conventional walking stick chair in the folded or unfolded state by virtue of a screw that is threaded drivingly to the sleeve. However, operation of the sleeve and the screw to convert the states of the conventional walking stick is inconvenient.
Taiwanese Patent Application No. 102112330 discloses another conventional walking stick chair including a stick and a sleeve that can be positioned relative to the stick through an easier operation. However, a positioning structure of the conventional walking stick chair is complex and therefore may raise the manufacturing cost of the conventional walking stick chair.